Spiral blade fan



p 1931. o. H. SPENCER 1,821484 SPIRAL BLADE FAN @W A %W Invcnior fiatenteci Sept. 1, 193i PATENT OFFICE OWEN' III. SPENCER, OF INDIANAPOLIS, INDIANA SPIRAL BLADE FAN Applicatlon am April 26,

This invention relates bo fan structures und particularly to the blast fan variety, und one feature of the invention is the provision f a combined fan hub und blades theref0r.

A fur ther feature 0f the in vention is the provision pf blades so arranged that a vacuum will be formedduring the rotation of the blades, thus increasing the volume of air to be icked up by the succeeding blade.

A urther feature of the invention is in so constructing the blades that they will assume a spiral outline from their inner to the'ir outer ends about one edge thereof, whereby the blast of air will be forced from the inner towards the outer ends thereof and the volume of air gradually increased from the inner 420 the outer ends of the blades, by which arrangement the ends of the blades will be fed by the remainder of the blade.

Other objects and advantages will be hereinafter more fully sei; forth and pointed out 4 in the accompanying specification.

In the accompanying drawings. which are mad' a part 0f this application,

F igure 1 is a fragmentary plan view 0f the fan structure. Y

F igure 2 is an edge elevation thereof with Parts in section and showing the difl'erent contours of the blade in full and dotted lines, correspondingto F igures 3 t0 6 ii1clusive.

Figure 3 Ts 21 sectiona'l view as seen on dotted line 3-3 Fig. 1.

' F igure 4 is a section 0n line 44 Fig. l.

Figure 5 is a section on line 5-5, Fig. 1,

Figure 6 is a section on line 66, Fig. l.

Referring t-0 the drawings, the numeral 1 indicates the hub of the fan structure, which is preferably substantially hollow and semi- 4 globular, having a bearing sleeve 2 centrally thereof, for the reception of a shaft.

F ormed on the periphery of the hub 1, und preferably integral therewith, are blades 3, the inner edges 4 thereof extending substan- 46 tially in a straight line from end to end, while the opposite edges 5 the'reof are curved substantially coincident to the curvature of the 'outer face of the hub 1, such curva;ture imparting a suizstsmtially spiral outline to the blades, from end to end.

1929. Serial N01 358,366.

The blades 3 are concave 011 one side, as indicated at 6, while the opposite faces there- 0f are convex, as indicated at 7, so that the blades Will readily gather air on the concave sides and gradually feed it towardsthe outewends of the blades, the volume of aira-t the outer ends of the blades being greater than at the inner ends thereof. At the same time the convex surfaces of the blades will create a vacuum adjacent one edge of the 60 blades, and thus gather a large volume 0f air to be pick(ed up by the next succeeding blade, so that; a greater volume "0f air will be expelled by the fan than can be created by the ordinary fan und. without increasing 6 the dimensions of the fan over the ordinary fan str1ictu1e.

The tilt 0f the, blades is greater at their inner ends, the tilt gradually decreasing to- Wards the outer ends of the Hades so that the extreme unter ends of the blades are more nearly flat, the degreeS of tilt being clearly shown in Figures 3 to 6. v

-By this arrangement the inner ortions of the blades serve partly as centri ugal flowing means which feed the flatter ends of the blades W ith air, said ends being calculated to drive the air thus fed, sideways with great forc.

This fan is designed primarily for use in connection with air cooled engines, the 0bject being to direc-t a maximum blast of an without increasing the diameter of the fan blades, owing to the limited space in which to mount a fan', and it will be readily seen that byShaping the blades as shown, a. far greater volume of air will be thrown by the fan than could be obtained with the use 0f the ordina.ry fan structure.

Whj le; the description und drawings 1llugtrate m a general way certain instrumentahties which may be employed in c&tryingthe inve'antion into efl'ect, it is evident that many modifications may be made in the various de tails without departin g from the scope ofthe 9 appended claims, it being understood that the invention is not restricted to the partipular examples herein described. 1

I claim as my i n vention:

1. In a fan sttixiztu'refa semi-globular hub,

a pair of blades attached ther eto with their inner ends conforming to the outer curved surface o f the hub, said blades being substantially concavo-convex in cross section throughout their length the concavo-convex curvatures gradually decreasing in extent from the inner to the outer ends of said blades, one edge of the blades extending in a. straight line from end to end with the stmight edge intersecting said hub substantially ab the apex 0f the hub and the opposite edge of the blade intersecting said hub substantially at the base line thereof, the transverse width of thebladgs gradually decreasing from their point of c0nnection with.

the hub to their outer ends.

2. In a fan structure, a semi-globular hub, a. pair of blades attached thereto, the inner ends of said blades be ing substantially coucavo-convex and the '=Quter ends substantially straight in cross sectionthe concavoconvex curvatures gradually lessianing from the inner to the outer (ands of said bla.des, one edge 0f each blade extending in a strai ht line from end t0 end und the opposite e ge being gradually curved inwardly from its inner end, the inner endof the straight edge uniting with the hub substantially ab the curved apex end of the hub and at one side v of the axis of the hub und the curved edge of the blade connecizing with the hub at the opposite or base end thereof und on the op posite side of the axis of the hub.

3. In a fzfn structure, a s1ibs tantially 001 5 noidal hub having a semi-oval surface, und blades radiating therefromthe inner or counecting ends of said blades extending spirally of"said hub from e nd .to end thereof a nd transversely thereof substantially one -half 40 the diameter of the hub, one edg6 of auch blade extending in a straight=line from end to end und the opoosite edge being gradually curved inwarly from its inner to its outer end with said curVed edge arranged spirally, whereby the extreme outer end oi the blade will extend substantially in a. straight line transversely 015 the axis of the hub and approximately in line with the apex 01 rounded end of the hub. 60 In testimony whereof, I have hereunto set xxy 1l;and on this the 25th day of March, 1929,

OWEN H. SPENCER. 

